An insightful opinion
1. The code I write is a response to what I currently understand of problem I currently have, using my current understanding of current tools. Expertise improves how big the "current" horizon is on understanding problems and tools, but the current-ness of the problem space and tool space are external factors. Either way, both personal growth and world changes (basically time) will and should invalidate code.
2. Code is an expensive liability against the Universal Bank of Entropic Chaos. We take on the liability of building and maintaining it so that we generate a complementary asset that does something we consider valuable. But there is always an initial price and compound interest to be paid. Expertise will reduce both the price and the interest rate, but neither can ever go to zero.
https://news.ycombinator.com/item?id=36208718